Electrical double layer (EDL) modulation in liquid–solid interfaces has been extensively studied as an easy and effective approach to harvest triboelectric energy from micromechanical wasted energy. Owing to the fluidity of liquids, the liquid–solid contact area in an EDL-based device, for example, a liquid droplet sandwiched between two substrates, can be modulated to a large extent by simply squeezing or releasing the two substrates. However, conventional EDL-based technology cannot fully exploit this advantage, and the relevant devices suffer from poor efficiency. Herein, we demonstrate a simple yet highly effective EDL-based energy harvesting device with a novel electrode design composed of a hydrophilic inner circular electrode and hydrophobic outer ring electrode allowing the best use of the liquid–solid interface, i.e., large modulation of the contact area. The contact area variations in the top and bottom substrates contribute in an opposite manner to the electric generation in a conventional device. However, the new electrodes are designed to ensure that the contact area variations in the two substrates contribute cooperatively to the energy generation. The new device increases the output power by approximately 30-fold compared to that of conventional devices. Moreover, the optimal design for higher power generation considering internal resistance is systematically investigated and theoretically verified. The feasibility of these devices is demonstrated by the instantaneous lighting of LEDs and long-term stability tests. This new concept can expand the possibility of EDL-based energy-harvesting devices.

液-固界面中的双电层 (EDL) 调制已被广泛研究为一种从微机械浪费的能量中获取摩擦电能的简单有效的方法。由于液体的流动性，基于 EDL 的设备中的液固接触面积，例如夹在两个基板之间的液滴，可以通过简单地挤压或释放两个基板在很大程度上进行调节。然而，传统的基于EDL的技术无法充分发挥这一优势，相关设备效率低下。在这里，我们展示了一种简单但高效的基于 EDL 的能量收集装置，其具有由亲水内圆电极和疏水外环电极组成的新型电极设计，可充分利用液固界面，即 接触面积的大调制。顶部和底部基板中的接触面积变化以相反的方式对传统器件中的发电做出贡献。然而，新电极的设计旨在确保两个基板中的接触面积变化共同促进能量产生。与传统设备相比，新设备将输出功率提高了约 30 倍。此外，系统地研究和理论验证了考虑内阻的更高发电量的优化设计。这些器件的可行性通过 LED 的瞬时点亮和长期稳定性测试得到证明。这一新概念可以扩大基于 EDL 的能量收集设备的可能性。顶部和底部基板中的接触面积变化以相反的方式对传统器件中的发电做出贡献。然而，新电极的设计旨在确保两个基板中的接触面积变化共同促进能量产生。与传统设备相比，新设备将输出功率提高了约 30 倍。此外，系统地研究和理论验证了考虑内阻的更高发电量的优化设计。这些器件的可行性通过 LED 的瞬时点亮和长期稳定性测试得到证明。这一新概念可以扩大基于 EDL 的能量收集设备的可能性。顶部和底部基板中的接触面积变化以相反的方式对传统器件中的发电做出贡献。然而，新电极的设计旨在确保两个基板中的接触面积变化共同促进能量产生。与传统设备相比，新设备将输出功率提高了约 30 倍。此外，系统地研究和理论验证了考虑内阻的更高发电量的优化设计。这些器件的可行性通过 LED 的瞬时点亮和长期稳定性测试得到证明。这一新概念可以扩大基于 EDL 的能量收集设备的可能性。